An olfactory display for virtual reality glasses

Abstract

Olfaction has not been explored in virtual reality environments to the same extent as the visual and auditory senses. Much less research has been done with olfactory devices, and very few of them can be easily integrated into virtual reality applications. The inclusion of odor into virtual reality simulations using a chemical device involves challenges such as possible diffusion into undesired areas, slow dissipation, the definition of various parameters (e.g., concentration, frequency, and duration), and an appropriate software solution for controlling the diffusion of the odor. This paper aims to present a non-intrusive, mobile, low cost and wearable olfactory display, and a software service that allows the developer to easily create applications that include olfactory stimuli integrated with virtual reality headset glasses. We also present a case study conducted with 32 people to evaluate their satisfaction when using the olfactory display. Our findings indicate that our solution works as expected, producing odor properly and being easy to integrate to applications.

Supplementary information: The online version contains supplementary material available at 10.1007/s00530-022-00908-8.

Keywords: Odor; Olfactory display; Virtual reality.

Fig. 1

Architecture overview

Fig. 2

Virtual reality glasses with an olfactory display

Fig. 3

Olfactory device State Diagram

Fig. 4

The developed virtual reality application

Fig. 5

How an application is developed with our asset in Unity. A sphere or box delimiting the odor volume is created. When the user is inside that volume the odor is automatically released

Fig. 6

Color scale towards the positive and agreeable ends of answer scales even if their experiences are negative

Fig. 7

Evaluation of user satisfaction. Histogram of responses for all questions for the two groups, compared with the curve of a normal distribution for the corresponding average and standard deviation. Group 1 AVG: 4.264, STDDEV: 0.816. Group 2 (control) AVG: 3.500, STDDEV: 0.927

Fig. 8

Averages for each question according to the two groups, normalized so 1 is the worst grade and 5 the best grade. Based on the results of our evaluation, we argue that the solution presented was a positive addition to our virtual reality application